How Long Does Heroin Stay in Your System?

The testing window for heroin use is likewise generally very short, although hair testing can detect its use in some cases even months later.

Heroin’s Presence in Your System

Heroin is a short-acting opioid with an especially short half-life of between 0.1 to 0.25 hours. 

For context, a drug’s half-life is how long it takes the body to eliminate about 50 percent of the drug currently present in its system. Typically, a drug will be almost entirely eliminated within about four to five half-lives. 

Heroin is an opioid closely associated with a rapid effect, although a user may maintain their high by continually using the drug as its effects wear off. This is common with short-acting opioids, and this repeated cycle of use leads to addiction more quickly. 

Factors That Affect How Long Heroin Stays in Your System

There are a number of factors that are going to impact exactly how long heroin (or any other drug) stays in your system. 

One of the most obvious is the amount of the drug you do. Using more of a drug generally makes it stay in your system at some detectable level for longer. Likewise, repeated, heavy use can also cause a person to have trace amounts stay in their body longer than would normally be expected. 

Certain traits of an individual drug user can also affect how long heroin stays in their system. Individuals who are larger, both in terms of being tall and heavy, tend to need more drugs to achieve a similar effect. They may process the same amount of a drug faster than someone smaller. 

For a few biological reasons, cisgender men also tend to process drugs faster and need more of a drug to affect them in the same way compared to cisgender women. Genetics can also play a factor, as can age, with older bodies often processing drugs less efficiently than younger bodies.

How Does Heroin Affect the Body?

Heroin is associated with a rapid, intense euphoric high. It is a drug considered to have significant abuse and addiction potential. Its short-lasting effect also means it is generally considered to have no practical medical applications. Although it did have a role in medicine in the past, this was before we understood its dangers and better, more modern medications that can perform the same tasks were developed.  

As discussed by the DEA, heroin is also associated with causing the following effects:

• A “twilight state” where one falls in and out of consciousness
• Drowsiness
• Respiratory depression
• Constricted pupils
• Nausea
• Warm flushing of the skin
• Dry mouth
• A feeling of heaviness in the extremities

Heroin can cause physical dependence and addiction. With repeated use, the body can adapt to the drug, causing a person to experience withdrawal if they are opioid abstinent for too long, which can make quitting heroin use much more difficult. 

Symptoms associated with withdrawal, which is often described as flu-like, include the following:

• Anxiety
• Diarrhea
• Hot and cold flushes
• Insomnia
• Muscle cramps
• Nausea 
• Vomiting
• Perspiration
• Watery discharge from eyes and nose

Heavy heroin use, and heavy opioid use in general, has the potential to cause a deadly overdose. This is generally due to respiratory depression getting so severe that the body can no longer draw in enough air to support itself, even if the person actively tries to breathe in more deeply than normal.

Summary of Estimated Testing Windows for Heroin

The following is a chart that notes the detection window generally attributed to various types of heroin drug tests. Note that these tests are often able to detect very small amounts of drugs in a person’s system, even if they no longer feel the effects of the drug. These windows can also be bigger or smaller depending on the specific situation of the individual being tested:

Test Type	Estimated Detection Window
Urine	< 1 day
Hair	< 90 days
Saliva	< 36 hours
Sweat	< 14 days

Heroin is actually fairly unusual in how short its detection windows are compared to other common drugs of abuse. 

While hair testing has a relatively large detection window, there are a few caveats to understand about this type of testing. First, it is generally considered relatively invasive, requiring that a piece of a person’s hair be cut for analysis. Second, it can take time for enough hair to grow in for testing purposes, and the detection window can be reduced if a person cuts their hair regularly.